336 DorAN: ON THE GERMINATION OF FUNGOUS SPORES 
3. Mature spores can germinate through a broader range of 
environmental conditions than can immature spores. 
4. Freshly mature spores can germinate through a broader 
range of environmental conditions than can old spores. As the 
spores age, viability at first decreases sharply after which it is 
only gradually lost. Longevity of spores is dependent on condi- 
tions of storage after detachment from the host. Moisture is 
of more importance than temperature in its effect on the length 
_of life of the spore. 
5. Spores of the Phycomycetes can germinate at the lowest 
minimum temperatures, followed in order by the urediniospores, 
the aeciospores, and the teliospores of the Uredinales. Aecio- 
spores have the lowest optimum temperatures for germination 
followed in order by urediniospores, conidia of Phycomycetes, 
teliospores, and the spores of the Imperfect Fungi. 
6. The nearer all conditions are to the optimum, the shorter 
the time required for spore germination. 
7. Competition or crowding inhibits spore germination. 
This is attributed to insufficient oxygen. 
8. Spores of the fungi studied germinated in either light or 
darkness. 
9. Precipitated moisture is unnecessary for the germination 
of some spores if water vapor is available. 
New HAmpsuire AGRICULTURAL EXPERIMENT STATION, 
DurHAM, New HAMPSHIRE 
LITERATURE CITED 
al 
Young, Harry C., & Cooper, E. H. A method for determin- 
ing the fungicidal coefficient of lime, sulphur and other 
common fungicides. Michigan Acad. Sci. Rept. 19: 221- 
236. =’ TO%7. 
2. Clark, J..F. Dissociation and toxic effect. Jour. Phys. 
Chem. 3: 263-316. 1899 
3. Duggar, B. M. Physiological studies with reference to the 
germination of certain fungous spores. Bot. Gaz. 31: 38- 
Ct... J 
4. Mains, E. B. Some factors concerned in the germination 
of rust spores. Michigan Acad. Sci. Rept. 17: 136-140. 
1915. 
